The role of carrier in sensitivity to chromium and cobalt.

Patients suffering from contact dermatitis caused by chromium sensitivity showed positive reactions to intradermal tests with chromium and cobalt chlorides. Patch tests to cobalt in unaffected and in healed eczematous skin areas gave negative results. A large number of chromium-sensitive patients also showed a positive intradermal test reaction to cobalt bound to human serum albumin and a negative reaction to cobalt bound to rabbit liver glycogen. It has been suggested that these positive reactions to cobalt are secondary sensitivities to cobalt, caused by cobalt-denaturated human serum albumin that is so similar to the denaturated product of chromium cations that the competent cells cannot distinguish between them.